JPS6029522B2 - Cleaning device for membrane support tubes for membrane separation equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cleaning device for a membrane support inspector for a membrane separator.

When the membrane separation equipment is operated for a long period of time, the permeation outflow hole of the waist support tube installed in the Katsu module that performs the membrane separation operation may become clogged, which makes it difficult for the membrane separation operation inside the membrane module to be performed smoothly. There are some problems that cannot be done. In order to prevent the above-mentioned events from occurring, the membrane supporter inside the membrane module was cleaned.

In this case, in order to increase the cleaning effect, air was injected into the cleaning liquid filled in the membrane module to perform bubble cleaning. At this time, due to the air pressure of the injected air, the pressure inside the membrane module filled with cleaning liquid (this pressure is P) increases, and the pressure inside the membrane support tube, that is, on the liquid side to be treated in membrane separation operation, increases. If the relationship with pressure (this pressure is P2) becomes P,>P2 (usually P, <P2), then
2 and is bent inward. On the other hand, the pressure exerted on the membrane when the cleaning liquid containing air bubbles is discharged is P. <P
2, in other words, when a positive pressure of P21P is applied to the membrane, the bent portion of the membrane stretches and returns to its original state.

If such an operation is repeated several times (at least 10 times or more), cracks will occur at the bent portions of the membrane, resulting in a significant decrease in the separation ability of the membrane. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art and to provide a cleaning device for a membrane support pipe for a waist separation device that prevents damage to the membrane during cleaning of the membrane support tube.

The cleaning device for a membrane support tube for a membrane separation device according to the present invention performs liquid cleaning by filling a membrane module with a cleaning liquid, and
In a cleaning device for a membrane support inspector for a membrane separator that performs air bubble cleaning by introducing air into the cleaning liquid, a cleaning air inflow valve is provided in a conduit for pressure-feeding the cleaning air, and the cleaning air is discharged from the membrane module. A gas-liquid separation tube for separating air from the cleaning liquid is connected to the membrane module, and an air discharge valve is provided in the gas-liquid separation tube. A control means is provided for opening the air exhaust valve and the cleaning air inflow valve in conjunction with each other so that the pressure on the cleaning liquid side does not exceed the pressure of the liquid to be treated during cleaning.

According to the above configuration, when cleaning the membrane support tube with liquid, both the cleaning air inflow valve and the air discharge valve are closed, and the membrane support pipe is cleaned by the hydraulic pressure of the cleaning liquid.

On the other hand, during bubble cleaning, both of the valves are opened and air is introduced into the cleaning liquid. At this time, inside the membrane module, the pressure on the cleaning liquid side becomes higher than the pressure on the processing liquid side due to the air introduced into the cleaning liquid, but the air separated by the gas-liquid separation pipe is discharged through the air discharge valve. As a result, the outer surface of the membrane support tube is cleaned with the membrane in a state where the pressure inside the membrane module is kept lower on the cleaning liquid side than on the treated liquid side, that is, the membrane is not subjected to back pressure. Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of the present invention. In the same figure, 1 is a membrane module that performs a membrane separation operation, and the membrane separation operation is performed between a stock solution inlet 2 and a concentrated solution outlet 3 in the membrane module 1. It will be held in Further, in the membrane module 1, a conduit 4 through which cleaning air is pumped and a conduit 5 through which cleaning liquid flows are integrally connected in the middle. The conduit 4 is provided with a cleaning air inflow valve 6 that is opened and closed by a control signal, and the conduit 5 is provided with a cleaning liquid inflow valve 7. On the other hand, the membrane module 1 is connected via a conduit 8 to a gas-liquid separation pipe 9 that separates the cleaning liquid from the air.
An air discharge valve 10 operated by a control signal is provided above the gas-liquid separation tube 9, and a cleaning liquid discharge valve 11 is provided at the bottom of the gas-liquid separation tube.

Furthermore, 12 is a control panel, and the control panel 12 sends out control signals for opening and closing operations in conjunction with the cleaning air inlet valve 6 and the air cost E valve. In the above configuration, cleaning of the membrane support tube provided in the membrane module 1 is performed by first opening the cleaning liquid inflow valve 7 and injecting the cleaning liquid into the membrane module through the conduit 5.

At this time, the cleaning air inflow valve 6 and the air exhaust valve 10 are in a closed state. Next, when performing air bubble cleaning, a control signal sent from the control panel 12 activates the cleaning air inlet valve 6 provided in the conduit 4 through which cleaning air is pumped at a constant pressure, and at the same time, The air discharge valve 10 provided in the gas-liquid separation pipe 9 is opened.

Therefore, the air pumped through the conduit 5 is dispersed within the membrane module 1, and after bubble cleaning of the membrane support section provided within the membrane module 1 is performed, the air and the contaminated cleaning liquid are separated in the gas-liquid separation tube 9. separated into The separated air is discharged from the air discharge valve 10, while the contaminated cleaning liquid is discharged from the cleaning liquid discharge valve 11 provided below the gas-liquid separation pipe 9. In this way, the cleaning air inflow valve 7 and the air discharge valve 10
Since the air after bubble cleaning is discharged from the air discharge valve 10 at the same time, the pressure inside the membrane module does not increase during bubble cleaning.

Therefore, according to this example, the membrane does not bend during bubble cleaning, so even if the number of cleanings increases, the membrane will not be damaged, and the separation performance of the membrane can be maintained over a long period of time. be. Next, FIG. 2 shows the main part of another embodiment of the present invention.

This embodiment differs from the previous embodiments in that the gas-liquid mixture during bubble cleaning is contained in the air discharge valve 10 in the gas-liquid separation pipe 9.
The point is that a baffle plate 13 is provided to prevent the water from being released from the water. According to this embodiment, it is possible to prevent the cleaning liquid from being discharged when the air discharge valve 10 is opened, and there is an effect that the separation efficiency of the gas-liquid mixture is improved.

As described above, the present invention provides a gas-liquid separation pipe having an air discharge valve after the pus module in order to discharge the cleaning air when cleaning bubbles, and opens and closes the cleaning air inflow valve and the air discharge valve in conjunction with each other. As mentioned above, according to the present invention, when cleaning air bubbles in the membrane support tube part, since no back pressure acts on the membrane, air bubbles do not flow back to the membrane. , the membrane will not be bent inward, and damage to the membrane can be prevented.

In addition, since the membrane support pipe can be used in combination with liquid cleaning and bubble cleaning, it is possible to effectively clean the permeation holes of the membrane support tube and the outer surface of the tube. A cleaning effect on the membrane itself can be expected due to its penetration into the membrane.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of a cleaning device for a membrane support inspector for a membrane separation device according to the present invention, and FIG. 2 is a block diagram showing the main parts of another embodiment of the present invention. 1... Membrane module, 2... Stock solution inlet, 3... Concentrated solution outlet, 4, 5, 8...
...Conduit, 6...Cleaning air inflow valve, 7...
... Cleaning liquid inflow valve, 9 ... Gas-liquid separation pipe, 10
... Air discharge valve, 11 ... Cleaning liquid discharge valve, 12 ... Control panel, 13 ... Baffle plate. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a cleaning device for a membrane support pipe section of a membrane separation device that performs liquid cleaning by filling a membrane module with a cleaning liquid and also performs bubble cleaning by introducing air into the cleaning liquid, a conduit for pressure-feeding the cleaning air is provided. A cleaning air inflow valve is provided, and a gas-liquid separation pipe for separating air from the cleaning liquid discharged from the membrane module is connected to the membrane module, an air discharge valve is provided in the gas-liquid separation pipe, and the cleaning air While the inflow valve and air discharge valve are closed during liquid cleaning, the air discharge valve and cleaning air inflow valve are opened in conjunction with each other to prevent the pressure on the cleaning liquid side from exceeding the pressure of the liquid to be treated during bubble cleaning. A cleaning device for a membrane support tube section for a membrane separation device, characterized in that it is provided with a control means.